This invention relates generally to orthotic appliances and constitutes further developments since our pending application Ser. No. 324,820, filed Nov. 25, 1981 which is incorporated herewith by reference.
Fairly recently, greater attempts have been made to provide footwear which is anatomically correct so as to not only increase the comfort of the wearer, but also to minimize fatigue and injuries. This requires an analysis of the typical human gait. When one is moving substantially in a single linear direction, the gait consists of three distinct phases. First, the heel strike phase occurs during which the foot is essentially a "mobile adapter" ready to conform to the topographical contours encountered. Some of the impact forces are dissipated through the ankle and leg bones to the upper torso, while other impact forces are translated into the foot. The proper dissipation and translation of these forces during the heel strike phase produce a natural shock absorption mechanism. Second, the transition or mid gait phase transforms the mobile adapter into a rigid lever whereby the mid-tarsal joint becomes locked preparing the foot for translation of the accumulated and developing forces in a stable manner throughout the foot during the remainder of said cycle and the ensuing final phase called toe roll. This is the final propulsive and translatory phase of gait. After the toe leaves the ground the swing phase of the next step begins. The critical phase is the mid-gait or transition phase where the foot is transformed from a "mobile adapter" to a "rigid lever". The optimum configuration for the ankle and tarsal joint at this point is to have the sub-talar joint in a neutral position as the mid-tarsal joint becomes locked and the foot becomes a "rigid lever". This allows the impact load to be properly dissipated and translated. While podiatrists have long been aware of the need to maintain the foot's proper orientation relative to the leg to provide a "rigid lever" and accordingly have prescribed orthoses for that purpose, the general populace rarely avails themselves of these services until after a certain amount of discomfort and/or damage has been done.
The following citations reflect the state of the art of which applicant is aware in so far as these patents appear to be germane to the patent process:
U.S. Pat. No. 2,669,814 Ritchey PA1 U.S. Pat. No. 2,680,919 Riggs PA1 U.S. Pat. No. 3,922,801 Zente PA1 French No. 1,240,066 Strasbach PA1 British No. 465,940 King.
Advertisment from Runner's World-July 1982-Saucony.
Of these, the patent to Ritchey appears to be of great interest since he teaches the use of an orthopedic device suitably positioned within a shoe or the like, in which the upper surface thereof has a complex contour addressed to the peculiarities of a given foot. The instant invention can be contrasted over this prior art by noting the contrasting ease with which the apparatus according to the instant application can be initially fitted to a person, or successively fitted as a function of time, while providing immediate relief.
Similarly, the patent to Riggs teaches the use of an insole type appliance having a compound contour like the Ritchey invention configured in such a manner as to provide foot relief based on Riggs' perception of a universal foot disorder.
Similarly, the Zente patent teaches the use of a liquid filled orthopedic apparatus comprised of a plurality of discrete internal liquid filled ampules which are strategically placed between upper and lower laminae and sealed in place to provide separate support for various parts of the foot.
The publication from the July 1982 edition of Runner's World provides a substantially horseshoe shaped plastic insert preferably formed of hytril adapted to be placed in a rear foot area of the shoe between a mid-sole and an upper. This device is predicated on the assumption that heel strike is initiated on the outside area of the foot initially, and accordingly attempts to distribute the load more evenly around the heel area presumably due to the intrinsic shock absorbtion properties attendant with the use of hytril. As exemplified in other prior art devices discussed supra, the associated insert defined in this citation is based on a predisposed conception of a generic foot malady, and a single insert is provided in an attempt to rectify a perception of a universal foot disorder.
The instant application is distinguished over these citations in that a plurality of instrumentalities are provided which are adapted to be selectively utilized by the wearer so that mixing and matching of orthotics defined by the instant application encompasses a broader spectrum of foot disorders than would otherwise be available in accordance with the prior art. Moreover, the device according to the instant application is distinguished over the known prior art in that a contour on the top surface of the insert is adapted to coact with the plantar surface of a person's foot in an especially beneficial way so that elogation of the foot along the longitudinal axis is provided for by associated distortion of the orthotic appliance with concomitant deformation of the appliance that urges the foot to transmit forces in a uniform manner free of unwanted torsions and or torsional forces and accordingly applies flexibility and variations to selectively engage a wide spectrum of foot problems.